REN and obesity due to melanocortin 4 receptor deficiency: The mechanism(s) underlying elevated sympathetic tone in people with hypertension are multi-factorial, but include activation of the renin-angiotensin-system [28], peripheral chemoreflex involvement [29], baroreflex dysfunction [30], chronic stress [31], poor organ perfusion [32], obesity as well as insulin and leptin levels [26, 33].